Here's what I'm most interested in. To what extent does one career actually make my performance either 1) substantively different (by "substantively" I mean different in what gets coded into a save file) or 2) emotionally different--that is, in the way it feels to me--in another career, and why, and how? I can already see that an irrevocable decision made in one career makes it feel very different to make a different choice in another career, even with something as simple as the Normandy's surgeon.
I suppose that in the back of my mind there's a looming question of a nearly odious nature: with Mass Effect 3, has BioWare created a work unlike any previous work of art in the combination of the plasticity of its performance materials and the irrevocability of the most important choices it affords?